1. Field of the Invention
The present invention relates generally to food dispensing devices and more particularly to an apparatus for dispensing viscous food products, such as ice cream toppings, hot fudge, nacho cheese, and other paste like products.
2. Prior Art
Bag-in-box packages have been in use for a number of years in packaging various products. An example is U.S. Pat. No. 3,173,579. These packages are used mainly for holding and dispensing liquids which will readily flow by gravity from the bag when the dispensing valve thereof is opened. However, they are not ordinarily used for containing and dispensing viscous and semi-viscous substances because of the requirement of dispensing mechanisms, such as pumps.
One solution to this problem has been the development of a bag having two chambers, as shown in U.S. Pat. No. 4,796,788. The first chamber is used to contain the food product and the second chamber is used, when supplied with compressed air, to compress the food product container for dispensing such products as salad dressings, ketchup, mustard, pizza sauce, etc. However, a problem with the system disclosed in the '788 patent is that a special, relatively expensive bag was manufactured, and the elasticity of the pressurized chamber is limited because of the physical requirements of the bag needed to contain the food products. In addition, no means are described for heating the food products contained in the bag.
U.S. Pat. No. 3,325,058 discloses an electrically heated receptacle and disposable containers therefore. A substantially rigid plastic tank is provided having a spigot at its lower end. The tank has a sloping bottom surface. An outer housing is provided for receiving the tank which has a heating element contained therein. As a result, when the tank is contained within the outer housing the food product contained within the tank may be heated and dispensed by a gravity feed. No means are provided for pressurizing the tank.
U.S. Pat. No. 3,837,533 discloses a container made of a light weight flexible sheet having a downwardly sloped portion in conformity with a slopped portion of a housing. The container has a nozzle used to dispense ketchup, mustard and mayonnaise. U.S. Pat. Nos. 2,766,907; 3,417,901; 3,508,686; and 3,941,258 each generally show multiple bladders.
U.S. Pat. Nos. 2,766,907; 3,494,513; 3,508,686; 3,941,258; and 4,120,425 each generally show pressure sources for dispensing products. U.S. Pat. No. 4,094,446 shows heating and dispensing of a food product using an electric pump.
Although each of the above listed patents discloses means for dispensing fluid products, the above listed prior art does not teach an inexpensive method of dispensing such fluid products nor a method of selectively heating such products when contained within a bag.